It is regrettable that you allow a forum for the kind of casual, stupid bigotry shown in letters such as Dana Ely's and Will Placek's The defects of their kind of thinking rest in a cluster of false, indeed absurd assumptions about private religion and public civil law.
First, Sharia is not some kind of monolithic set of beliefs held by all Muslims, but, properly understood, reflects the effort on the part of individual Muslims to draw out a personal code of conduct in relation to others of the faith and those not of the faith, not unlike the efforts of religious Christians and Jews to derive moral rules from sacred texts and generations of their interpreters.
Second, American Muslims, like all other groups of previous immigrants, came to America for the unique combination of economic and religious freedom which America offers, despite the lingering fears and terrors of new arrivals which have always marred the immigrant experience, both for those suffering from these irrational fears and hatreds and for those victimized by them.
Third, unless our Constitution and laws are amended, civil law will always triumph over denominational codes of conduct, whether Sharia, in the case of Muslims, Halacha, in the case of at least some observant Jews, or canon law, in the case of Roman Catholics.
Fourth, Muslims in America are a small minority and, under virtually any scenario, will remain such. Thus, even should some American Muslims wish Sharia to prevail in America (and every survey indicates that few of them wish this), their power to do so is extremely limited.
Fifth, given the freedom Americans enjoy to join a denomination or to leave one, there is no legal way for anyone of any faith to be compelled by their respective faith's legal code when they can escape such a code any time they wish by leaving that faith tradition.
Finally, it never occurs to those fanning fears of Sharia that those Muslims who choose to follow a version of Sharia do so in America precisely because they are free to do so, and see the exercise of their religion as an essential freedom. It is the ultimate irony that those, who through fear and hatred, would deprive American Muslims of their religious freedom are the ones who unwittingly are on track to choke off freedom for all.